I. Field
The following relates generally to wireless communication, and more specifically to determining a frequency offset for a signal received over a wireless channel.
II. Background
Wireless communication systems are widely deployed to provide various types of communication content such as, e.g., voice content, data content, and so on. Typical wireless communication systems can be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple-access systems can include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like.
Generally, wireless multiple-access communication systems can simultaneously support communication for multiple mobile devices. Each mobile device can communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations. Further, communications between mobile devices and base stations can be established via single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth.
MIMO systems commonly employ multiple (NT) transmit antennas and multiple (NR) receive antennas for data transmission. A MIMO channel formed by the NT transmit and NR receive antennas can be decomposed into NS independent channels, which can be referred to as spatial channels, where each of the NS independent channels corresponds to a dimension. Moreover, MIMO systems can provide improved performance (e.g., increased spectral efficiency, higher throughput and/or greater reliability) if additional dimensionalities created by the multiple transmit and receive antennas are utilized.
Wireless signals received at a mobile device, whether sent by a multiple output or single output transmission, can typically be replicated at the device for analysis, demodulation, or other forms of signal processing or data analysis. Where a replica fails to accurately represent the transmitted signal, signal corrections can be implemented. For instance, if a received signal and device-generated replica are shifted in frequency or phase, an offset can be determined and utilized as a correction factor. The received signal or the replicated signal, or both signals in some instances, can be adjusted based on the offset/correction factor. Accordingly, analysis of the received signal can more accurately reflect data transmitted by the transmission system.